System of control for electric motors.



E. s. Z-UBK. SYSTEM OF CONTROL FOB ELECTRIC MOTORS.

rum-r1011 r1121) an. a. 1911.

, Patented Sepf 8,1914.

ATTORNEY wimEss'Es UNITED STATES PATENT curios.

EMERSON ZUCK', OF CLEVELAND, 0510, ASSIGNOR T0 WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORIQRA'IION OF PENNSYLVANIA.

SYSTEM OF CONTROL FOR ELECTRIC MQTORS.

To all whom it may concern:

Be it known that I, EMERSON S. ZUoK, a citizen of the United States, and a resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented a new and useful Improvement in Systems of Control for Electric Motors, of which the following is a specification.

My invention relates to systems of control for electric motors and it has special reference to the control of motors used for industrial purposes, though it is also applicable to the control of electric railway motors.

One object of my invention is to provide an automatic system of control that shall be simple in arrangement and construction and shall embody the operating advantages of previous automatic control systems and the added advantage of reducing the number of unit switches to a minimum.

Another object is to provide selective means for notching up the controller automatically in accordance with predetermined current conditions of the motor circuit. A still further object is to provide a control system that will not only automatically bring the motor up to a full running speed, but will also allow operation at any desired intermediate speed.

Usually, automatic operation is obtained by means of a master controller for gover s ing the auxiliary circuits which control a plurality of main unit switches, so arranged as to close in a predetermined sequence and under predetermined conditions, such a sys tem involving a complicated system of wiring and a relatively large number of unit\ switches.

According to my invention, I combine the the controller drum being so arranged that,

by alternately. changing connections from one unit switch to another, the circuit completions and interruptions may be handled by a minimum number of switches.

Obviously, my invention is not restricted Specification of Letters Patent,

Application filed January 3, 1911.

Patented Sept.- 8, 1914. Serial No. 800,571.

to astationary drum and movable member as any suitable relatively movable members may be employed for accomplishing the purpose.

lhe' 'automatic features of my invention are secured by means of a series relay, ad- ]usted for predetermined conditions and adapted to alternately energizetwo electromagnets, according as the motor current is grgater or less than a predetermined value. the common movable core of the magnets may be moved in one direction or the other,

depending on which electro-magnet is enerlar manner, it is only necessary to interrupt the above mentioned magnet circuits in order to allow operation at any intermediate position of the controller.

The Figure l of the accompanying drawing is a diagrammatic view of a'system of automatic control which embodies my invention as applied to a single motorarranged to operate in one direction. is an elevation oi a portion of the controller and shows clearly the relation and operation of the movable controller member with respect to the ratchet and thecontroller drum.

Referring to the accompanying drawin the reference numerals having the same significance in both figures, a motor having an armature 1 and field magnet winding 2,.is connected to a source ofpower 3 and 4 through a plurality of resistance'elcmeuts 5, 6, 7-. 8, 9 and ill, the motor connections and the amount of resistance connected in circuit therewith being determined by the relative positions of the movable contact member ll which cooperates with stationary controller drum 12, a development of which is shown.- The movable contact mem- The series relay 16, having a winding 17 l and upper and lower contact terminals 18 and 19, is constructed and adjusted to energize the operating electromagnets 22 and 23, respectively, according as the current in the motor circuit exceeds or falls below a predetermined normal value; the movement of the common core member of these magnets being transmitted to the movable contactmember of the controller by means of apaw -ancl-ratchet mechanism.

A. lever arm 27, pivoted at 28 and held in a mid position by springs 29 and 30, is con* nected to the mid point of the common movable core 31 by a pin,,pawls 33 and 3% being mounted upon the lever arm, at opposite sides of the pivot 28 in such manner that movement of the core 31 in one direction causes the ratchet 35 to be advanced by one pawl, while movement in the other direction advances the ratchet by means of the other pawl. The contact member 11 is secured rigidly to the ratchet 35 by a bar 25. The function of spring 36 is to maintain the pawls in engagement -with the ratchet.

Two unit switches 37 and 38 having stationary contact terminals, movable contact terminals and energizing windings 40-l1 and l3-4 l45, respectively, are ar ranged to handle the makes and breaks of the motor circuits, as governed by the controller.

In conjunction with th electrically operated switch 47, which is normally in a closed position, is a single polo double throw switch 48, by means of which the switch 47 qua-y be opened, thus breaking the circuit of the energizing magnets 22 and 23 and thereby preventing further movement of the controller member. The double pole single throw switch 50, is a master switch, the closure of which causes the motor to be auton'iatically brought up to speed.

. will be evident to those skilled in the he controller of 'my invention is pted to manual operation, in series rels the o erating atchet mechanism, and ie aux- "ches ":7, l8 and 50 may be dis- ,h, the positions oi the cont oller then being controlled by the hand ,rator.

tion of and conner strated are as tolls rest and the various pieces of ap cccupying the positions shown in the drawing, the master switch 50 is closedto the negative side of the line. The circuit thus completed energizes electro-magnet 23 which causes the movable core 31 to be attracted and the lever arm 27 to move upon its pivot 28 in such a manner-that the pawl 33 advances the ratchet 35, thereby moving controller member 11 into position a.

1n the position a, a circuit is established from the source 3 through. conductor 60, master switch 50, conductor 61, magnet winding 45 of the unit switch 38, conductor 63, ring segment 64:, bridging contact terminal 15, ring segment 65, conductor 66, conductor 67, conductor 57 and series relay winding 17 to the negative side of the sup ply circuit. Completion of this circuit ener-- gizes the winding of unit switch 38 and causes it to close the motor circuit through all of the resistance sections 5, (3, 7, 8, 9 and 10, conductor 70, ring segment 71, bridging contact, terminal 1 1, ring segment 72, conductor 73, moving contact terminal 44 and stationary contact terminal ofthe unit switch 351, conductor 57 and series relay winding 17 to the negative supply line. As the motor is thus thrown upon the line, the excess motor current causes the series relay 16 to-disengage lower terminals '19 and engage upper contact terminals 18, thus deenergizing the clcctro-magnct 23 and encrgizing electro-magnet 22 by way of conduc-- tor 52, upper contact terminals 13, cm'iductmr 75, winding 20 of clwtro-inagnet 22, conductor55, switch l7, conductors 5' 3 and 57 and coil 17 to the negative linen previously described. The electiomagnet then causes the movable controller contact member to be advanced to position b, by means of the pawl 3. and theratchet 35. v

In position I); the circuit connections remain unchanged until the motor current drops below the value for which the series relay is adjusted. .lhe'relay then bridges its lower contact terminals 19, thus rendering the magnet 22 incflective and energizing the magnet 23, through the devices bearing the follmving reference numerals: 52, 19, as, 50, 5 1, 21', 55, 17, 56, 57 and 17 to the negative line.

The magnet 23, being again energized, causes the nvl 83 in advance the movable controller member 11 into position 8, to ablish rzmncctions through the, energizing winding oi the unit switch EB-Tby way of dcvhies 52, 77, 78, 13, 7t), 80, 4:2, 81, 57 and 17. The closure of switch 37 completes the motor circuit through devices 1, 2, 5, 6, 1'7,

' a, a, s3, 84, 12 85, so, 41, 40, .57 and 17,

and short-circuits the resistance element 10, whereupon the motor current suddenly 1ncreases and causes the series relay to engage upper contacts 18, thus denergizmg magnet 23 and euergizin magnet 22, as previously described, to a Vance the movable controller member to position (2.

moving into position (1, the insulated terminals 88 and 89 open the circuits through the energizing winding 45 of the unit switch 38, and the motor circuit through resistance section 10, respectively, thus saving the switch 38 open and resist case 10 entirely out out of circuit. The circuit connections thr ugh unit switch 37 remain unchanged until the motor current dccrcases sutliciently to allow the series relay to be disengaged from its upper terminals 18 and to bridge its lower terminals 19, when magnet 23 is energized, as hereinbeiforc described, and controller member 11 advances to position a.

As the contact member occupies, successively, the positions e to n, the resistance elements 9, 8, 7 6 and 5 are graduallycut out of circuit until, in the last position a, the motor is connected directly across the s 23:62, with no resistance in series with it. detailed description of the circuit and operations from the position e to position a is omitted on account of the similarity of such circuits and operations to those already described and the ease with which one skilled in the art, can readily trace such circuits and note. resulting operations.

In thelast position 11, the bridging con-' tact member 15 engages the auxiliar terurinal 90, thus causing a circuit to he es tablished from the source 3, through devices 60, 50, 61, 91, 47, 92, 48, 93, 94, 90, 15, 9 5 67, 57 and 17 to the negative line, thus energizing the winding 47 of switch 47 and causing said switch to open the circuit of the operating magnets 22 and 23,-and conscqneutl'y preventing further movement of the cor'itroller contact member.

To discontinue operation, switch i8 is opened to denergize the winding .47 of switch '47 and allow said switch to close and complete the circuit through the operating magnet 23, as previously described, controller contact member being thus advanced to its ofi position, after whit-lithe master switch may be opened.

To operate at any intermediate position of the controller, it is only necessary to cause the switch 48 to make contact with contact terminal 97, in which case the winding 47 of the switch 47 is energized by way of devices 60, 50, 61, 91, 47, 92, 48, 97, 98, 67, 57 and 17, and the switch is consequently opt-med, such action opening the circuit of the magnets 22 and 23 and preventing further movement of the controller contact member 11;

In order to continue from any intermediate operating position, the switch 48 is closed'upon the contact terminal 93 to -deenergize the'windin 47 of the switch 47 and allow said switc to reestablish connections for the operating magnet 23 and thus restore the automatic operation of the controller.

While I have illustrated and described specific arrangements and connections of the apparatus, I desire it to be understood that the details of construction and relative arrangement of the devices may be materially s0 varied from what is shown in the drawing and hereinbefore described without departing from the scope and spirit of my invention, and I further desire that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

'1, The combination with a controller comprising relatively-stationary and-movable cooperating members, of automatic selectively controlled electro-responsive means for alternateiy advancing the movable member through its successive steps.

2. The combination with a controller comprising relatively stationary and movable cooperating members, of automatic electro-responsive means for alternately advancing the said movable member through successive operating positions, said means comprising a plurality of actuating electio-magnets 10c and a aWLand-ratchet mechanism.

3. T e combination with a controller comprising relatively stationary and' movable 00- operating members, of an electro-responsive means for automatically actuating the mov- .able member step-by-step through successive operating positions, said means comprising a pawl-and-ratchet mechanism and-a plurality of electro-ma-gnets which are selectively'energized according to current condi- 11c tions of the motor circuit.

. 4. The combination with a controller comprising relatively stationary and movable cooperating members, of selectively controlled electro-rcsponsive means of advancing the movable member through its successive positions, said means being dependent upon the current conditions of the motor circuit.

5. The combination with a controller comprising relatively stationary and movable 00- operating members, of automatic electro-responsive means embodying a plurality of electromagnets for alternately advancing said movable member step-by-step through successive operating positions.

6. In a control system for electric motors, the combination with a supply circuit, a motor, a starting resistance therefor, and a plurality of independently operated switches l for governing the motor circuits, of a con- 13o troller comprising movable and stationary members which are adapted to. provide the necessary circuit connections, electro-responsive means for advancing said movable member step-by-step through successive positions, and selective means dependent upon circuit conditions for alternately energizing said electro-responsive means.

7.. In a control system for electric motors, the combination with a supply circuit, a motor, a starting resistance therefor, and a single pair of independently operated main switches, of a controller comprising relativelystationary and movable cooperating contact members for governing the circuit connections for said switches, and electroaresponsive means for advancing said movable member through its successive posi tions.

8. in a control system for electric motors, the combination with a supply circuit, a. motor, a starting resistance therefor, and a single pair of independently operated line switches, Of a controller comprising relatively stationary and movable cooperating contact members for alternately governing the circuit connections of said pair of line switches.

9. In a control s stem for electric motore, the combination \vith a supply circuit, a motor and a starting resistance therefor, of a single pair of electro-responsive line switches, governing controller comprising relatively stationary and movable coiipcrating' contact members, and selectively controlled electro-responsive means for alternately advancing the member intermittently through its successive positions.

10. in a control system for electric Inotors, the combination with a supply circuit, a motor and a starting resistance therefor, ot a single pairot independently operated lino switches and a controller comprising relatively stationary and. movable cooperating members for governing the connections of said switches.

11. The combination with a controller comprising relatively stationary and movgovern the acceleration of an electric motor,

of elcetro-magnetic means adapted to be energized when said movable member IS in its last position for automatically interrupting the circuit of said electro-responsive means.

12. The combination with a" controller comprising relatively stationary and movable cooperating members and electro-responsive means for alternately and selec-- tively advancing the movable member through its successive positions, of an elec-. tric'ally operated switching device adapted to be automatically energized under predetermined conditions for preventing said movable controller member from advancing beyond its full running position.

13. The combination with a controller comprising relatively stationary and movable cooperating members, and a plurality of electro-magnets and apawl-andmatchet mechanism for advancing said movable "member through its successive positions, of

an electrically operated switching device adapted to open the circuit of said electroniagnets when the movable controller member is in its last position.

14;. The combination with a controller comprising relatively stationary and movable cooperating members and electro-responsive means for automatically advancing the movable member through its successive positions, of I an electrically operated switching device adapted to be automatically energized when the movable member is in its last operating position for interrupting the circuit of said electro-responsiye means, and an auxiliary manually operated switching device for interrupting said circnitat any intermediate position.

' In testimony whereof, I have hereunto subscribed my name this twentieth day of December 1910.

EMERSON S. .ZUCK.

\Vi tnesses CHAS. E. 'SGHMELL,

F. Noon, 

